SOLARIUM. 233 



glaze over the lilac tint, and three rows of spots on the central 

 area of the lower disk. 



18. perdix (f. 17, IS), Hinds. — T. depresso-conica, sulcis 

 subcontiguis (corpore lsevi excepto) subobsolete radiata, spiraliter 

 unisulcata. Anfractuum zona superior Candida, maculis ferrugi- 

 neis (saepiusque remotis) ornata : area infra sulcura profundum 

 sublatum pallida, aliquando maculis linearibus ferrugineis (ssepe 

 autein obscuris) superne marginata. Cingula peripheric peran- 

 gusta, arete tenuiterque crenata, et, cum cingulo suprasuturali 

 cingulisque externis disci inferioris, albo et ferrugineo articulata. 

 Sulcus peripheric profundus, in latitudine cingula vicinaaemulans, 

 baud filosus. Area; basalis medium sulcis radiatum, pallide albo- 

 purpurascens, tantum ad marginem interiorem obscure macula- 

 turn. Crena3 umbilici vix uuice ampli, candidae, perrnultas. 



14. Dunkeri (f. 29, 30), Hartley. — T. conica, baud mult urn 

 depressa, saepe trochiformis. Discus superior sicut in S. perdice, 

 sed magis fulvus, et nonnunquam maculis linearibus parvis dis- 

 tantibus subbrunneis, in seriebus spiralibus paucis, subobsolete or- 

 natus ; cingula, etiam, latiora multoque confertius crenata, macu- 

 lis brunneis confertioribus magisque conspicuis, picta : carina lata. 

 Discus inferior (in exemplis pulchrioribus) sicut in S. pnrpurato : 

 area media lineis nonnullis brunneis interruptis aliquando ciucta : 

 sulci radiantes conspicui. Crense umbilici magnae, plerumque 

 brunneae. OLs. The keel is peculiarly broad below. The exte- 

 rior spiral sulci of the lower disk are almost cancellated in imma- 

 ture examples. 



15. l^vigatum (f. 21, 22), Lamarck. — T. subdepresso-conica, 

 inferne albida, superne violaceo pallido magis minusve tincta, 

 luteo-fuscesceute vel fulvo notata. Anfractus sulcis profundis 

 2 (praeter eum qui cingulum elevatum super suturam modice 

 eanaliculatam praecedit) cincti; vittte superiores 2 ajquales, tertia 

 aliquantulum latior, cingulum angustissimum. Vittaa apicem 

 versus oblique decussatse, labrum versus laevigata; ; utraque ma- 

 culis informibus, prima magnis et distantibus, secunda et tertia 

 parvis et saspius spiraliter linearibus, notata. Peripheric cingula 

 subaequalia ; sulcus ejus superior subangustus, inferior latus, 

 haudque filosus. Area media basis magis minusve laevis, mar- 

 ginem exteriorem versus maculis magnis irregulariter circum- 

 scripta, alibi lentiginibus linearibus parvis frequentibus cincta. 

 Crena; umbilici coarctati magna;, plerumque albida', aliquando 

 ferruginese. Obs. The edge of the pillar is apt to be crenated, 

 and the umbilical wall is usually spirally striated in fine examples. 



